Realization of high-pressure dry methane reforming by suppressing coke deposition with Co-Rh intermetallic clusters

It is economical to perform methane and carbon dioxide reforming under high-pressure and temperature con-ditions, but the harsh operation condition poses a grand challenge for coke-resistant catalyst design. We report herein that surface-segregation-free Co1Rh3 clusters are stable catalysts under 20 bars at 850 oC. Microkinetic analysis discloses that balanced and lowered surface coverages of C* and O* constitute the most abundant re-action intermediates on Co1Rh3 clusters at elevated pressures, with respect to that of the monometallic ones, thus avoiding surface carbon accumulation or surface oxidative deactivation. Moreover, density functional theory calculations of carbon atom nucleation discloses that adsorbed carbon transformation to refractory, graphene-like carbon is suppressed on Co1Rh3 cluster surface, owing to increased energetic barrier and ensemble size, hence, only CO2 gasifiable soft carbon could form. The revelation of the electronic/geometric features of Co1Rh3 is regarded to provide a guidance for future coke-resistant catalyst design.